A polymer having a melt index of from about 0.5 g/10 min to about 4.0 g/10 min and a density of equal to or greater than 0.96 g/cc which when formed into a 1-mil film displays a moisture vapor transmission rate ranging from equal to or greater than about 0 to equal to or about 20% greater than X where X=k1{−61.95377+39.52785(Mz/Mw)−8.16974(Mz/Mw)2+0.55114(Mz/Mw)3}+k2{−114.01555(τ)+37.68575(Mz/Mw)(τ)−2.89177(Mz/Mw)2(τ)}+k3{120.37572(τ)2−25.91177(Mz/Mw)(τ)2}+k4{18.03254(τ)3} when Mw is from about 100 kg/mol to about 180 kg/moL; Mz is from about 300 kg/mol to about 1000 kg/mol; τ is from about 0.01 S to about 0.35 s; k1 is 1 g/100 in2·day; k2 is 1 g/100 in2·day·s; k3 is 1 g/100 in2·day·s2; and k4 is 1 g/100 in2·day·s3.